Multi-cylinder rotary type compressor

ABSTRACT

A multi-cylinder rotary type compressor designed to reduce intake loss and noise. The multi-cylinder compressor includes first and second compressing compartments partitioned from each other; first and second intake ports communicated with the first and second compressing compartments, respectively; and a communication hole located adjacent to the first and second intake ports to communicate the first compressing compartment with the second compressing compartment.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No. 2004-73807, filed on Sep. 15, 2004 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a multi-cylinder rotary type compressor and, more particularly, to a multi-cylinder rotary type compressor, designed to reduce intake loss and noise caused by intake of a refrigerant.

2. Description of the Related Art

Generally, as for rotary type compressors comprising only one compressing compartment, since a ring piston inside the compressing compartment is rotated in a state of being eccentric against the center of a rotational shaft, there occurs a problem of severe vibration caused by severe variation in rotational torque and disequilibrium of mass during compression of gas. Accordingly, in order to solve the problem, multi-cylinder rotary type compressors are provided, which comprise separate compressing compartments provided at upper and lower portions of the compressor, and ring pistons to rotate in opposite dispositions within the respective compressing compartments, thereby minimizing the variation of the rotational torque, and the disequilibrium of mass.

One example of such a multi-cylinder rotary type compressor is disclosed in Japanese Patent Laid-open Publication No. 2001-153079 (Laid-open Date: Jun. 5, 2001). The compressor comprises a first cylinder body provided at an upper portion thereof and having a cylindrical first compressing compartment formed in the first cylinder body, a second cylinder body provided at a lower portion and having a cylindrical second compressing compartment formed in the second cylinder body, and a partition plate between the compressing compartments. The compressor further comprises first and second ring pistons to compress a refrigerant gas while eccentrically rotating in a state of maintaining opposite dispositions within the respective compressing compartments upon rotation of the rotational shaft, and first and second intake ports communicated with inner portions of the respective compressing compartments to intake the refrigerant gas into the compressing compartments.

In such a multi-cylinder rotary type compressor, the first and second cylinder bodies respectively constituting the compressing compartments have a lower height than that of the single cylinder compressor having the same capability as that of the multi-cylinder rotary type compressor, whereby the diameters of the first and second intake ports of the respective compressing compartments are limited. Accordingly, since the multi-cylinder rotary type compressor has a large resistance against the intake flow due to a small cross-sectional area of each intake port, it has a problem of enlarged intake loss and intake noise due to insufficient intake amount of gas through the respective intake ports when intake volumes of the respective compressing compartments are rapidly increased (that is, when intake amounts of the gas are rapidly increased).

SUMMARY OF THE INVENTION

The present invention has been made in view of the above and other problems, and an aspect of the present invention is to provide a multi-cylinder rotary type compressor, designed to reduce intake loss in respective compressing compartments without increasing cross-sectional areas of intake ports of the respective compressing compartments.

It is another aspect of the present invention to provide a multi-cylinder rotary type compressor, designed to reduce intake noise of the compressor.

Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.

In accordance with one aspect, a multi-cylinder rotary type compressor is provided comprising: first and second compressing compartments partitioned from each other; first and second intake ports communicated with the first and second compressing compartments, respectively; and a communication hole located adjacent to the first and second intake ports to communicate the first compressing compartment with the second compressing compartment.

The multi-cylinder compressor may further comprise first and second cavities recessed a predetermined depth on inner surfaces of the respective first and second compressing compartments so as to be adjacent to the communication hole.

The first and second cavities may be located opposite to the communication hole.

The multi-cylinder compressor may further comprise: first and second cylinder bodies constituting the first and second compressing compartments, respectively; first and second compressing devices disposed within the first and second compressing compartments, respectively; a rotational shaft penetrating through the first and second compressing compartments to drive the first and second compressing devices; a partition plate disposed between the first and second cylinder bodies; and first and second shaft supporting members provided opposite to the partition plate to close openings of the first and second compressing compartments, respectively, while supporting the rotational shaft.

The communication hole may be formed through the partition plate.

The first and second cavities may be formed on the inner surfaces of the first and second shaft supporting members, respectively, so as to be opposite to the communication hole.

The first and second compressing devices may comprise first and second eccentric portions provided to the rotational shaft within the first and second compressing compartments so as to be eccentric in opposite directions to the rotational shaft, respectively; first and second ring pistons coupled to outer surfaces of the first and second eccentric portions within the first and second compressing compartments, respectively; and first and second vanes to partition an inner space of the first and second compressing compartments while linearly traveling in a radial direction according to rotation of the ring pistons, respectively.

The communication hole, and the first and second cavities may have a maximum width less than a thickness of the ring pistons in the radial direction.

In accordance with another aspect, a multi-cylinder rotary type compressor is provided comprising: first and second compressing compartments partitioned from each other; first and second compressing devices to perform compressing operation in a state of being eccentric in opposite directions within the first and second compressing compartments, respectively; first and second intake ports communicated with the first and second compressing compartments, respectively; and a communication hole located adjacent to the first and second intake ports to communicate the first compressing compartment with the second compressing compartment.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional view illustrating the construction of a multi-cylinder rotary type compressor in accordance with one embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along line II-II′ of FIG. 1;

FIG. 3 is a cross-sectional view taken along line III-III′ of FIG. 1;

FIG. 4 is a detail view of circle IV of FIG. 1;

FIG. 5 is a perspective view illustrating the construction of communication hole, and first and second cavities of the multi-cylinder rotary type compressor in accordance with the embodiment of the present invention;

FIG. 6 is a view illustrating the cavity of a ring piston of the multi-cylinder rotary type compressor in a state of being partially closed in accordance with the embodiment of the present invention; and

FIG. 7 is a cross-sectional view illustrating the construction of a multi-cylinder rotary type compressor in accordance with another embodiment of the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE, NON-LIMITING EMBODIMENTS OF THE INVENTION

Reference will now be made in detail to illustrative, non-limiting embodiments of the invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout the drawings. The embodiments are described below to explain the invention by referring to the figures.

Referring to FIG. 1, a multi-cylinder rotary type compressor in accordance with one embodiment of the invention comprises a motor 20 disposed at an upper portion inside a closed container 10 to generate a rotational force, and a compressing part 30 disposed at a lower portion inside the closed container 10 while being connected to the motor 20 through a rotational shaft 21.

The motor 20 includes a cylindrical stator 22 fixed to an inner surface of the closed container 10, and a rotor 23 rotatably installed inside the stator 22 while being coupled at the center of the rotor 23 to the rotational shaft 21.

As shown in FIGS. 1 to 3, the compressing part 30 includes a first cylinder body 33 provided at an upper portion thereof and having a first cylindrical compressing compartment 31 formed in the first cylinder body 33, a second cylinder body 34 provided at a lower portion and having a second cylindrical compressing compartment 32 formed in the second cylinder body 34, and first and second compressing devices 40 and 50 installed within the first and second compressing compartments 31 and 32 to compress a gas, respectively. The rotational shaft 21 extended from the motor 20 is installed to penetrate though the center of the first and second compressing compartments 31 and 32 so as to operate the first and second compressing devices 40 and 50 within the first and second compressing compartments 31 and 32.

The compressing part 30 includes a partition plate 35 disposed between the first and second cylinder bodies 33 and 34 in order to partition the first compressing compartment 31 provided at the upper portion of the compressing part from the second compressing compartment 32 provided at the lower portion of the compressing part, and first and second shaft supporting members 36 and 37 mounted on an upper side of the first cylinder body 33 and a lower side of the second cylinder body 34, respectively, so as to close upper and lower openings of the first and second compressing compartments 31 and 32, respectively, while supporting the rotational shaft 21.

The first and second compressing devices 40 and 50 respectively installed within the first and second compartments 31 and 32 include first and second eccentric portions 41 and 51 provided on outer surfaces of the rotational shaft 21 in the compressing compartments 31 and 32, first and second ring pistons 42 and 52 rotatably coupled to outer surfaces of the first and second eccentric portion 41 and 51 with outer surfaces of the ring pistons 42 and 52 in contact with inner surfaces of the compressing compartments 31 and 32 to allow the first and second eccentric portions 41 and 51 to rotate, first and second vanes 43 and 53 to partition the inner space of the compressing compartments 31 and 32 into an intake side and a discharge side while linearly traveling in a radial direction within the respective compressing compartments 31 and 32 according to rotation of the respective ring pistons 42 and 52 (see FIGS. 2 and 3). At this time, the first and second eccentric portions 41 and 51 are disposed on the outer surfaces of the rotational shaft 21 to be eccentric in opposite directions. This construction is provided for the purpose of minimizing variation in rotational torque and reducing vibration upon compressing operation by maintaining balance between opposite sides of the rotational shaft.

The first and second cylinder bodies 33 and 34 have first and second intake ports 61 and 62 connected to first and second intake pipes 63 and 64, respectively, such that the gas flows in first and second cylinder bodies 33 and 34 therethrough. The first and second supporting members 36 and 37 have first and second discharge ports 65 and 66 in order to discharge a compressed gas (see FIGS. 2 and 3). In FIG. 1, reference numeral 13 denotes an accumulator installed within a refrigerant intake pipe 11, and reference numeral 12 denotes a discharge pipe to guide the compressed refrigerant inside the closed container 10 to the outside.

In such a multi-cylinder rotary type compressor, as the first and second eccentric portions 41 and 51 within the first and second compressing compartments 31 and 32 are rotated in a direction of arrow A by virtue of driving of the motor 20 while maintaining opposite disposition within the compressor, the first and second ring pistons 42 and 52 intake the gas from the first and second intake ports 61 and 62, and discharge the compressed gas towards the first and second discharge ports 65 and 66 while eccentrically rotating within the first and second compressing compartment 31 and 32, respectively, thereby performing a compressing operation.

Upon the compression of the gas, since the first and second eccentric portions 41 and 51 are eccentric in opposite directions to each other, the compressing compartments 31 and 32 always provide different intake volumes from each other, one of which is alternatively higher than the other, and this phenomenon is repeated with a phase difference of 180 degrees within the compressing compartments 31 and 32. That is, in the case where the first compressing compartment 31 has an increased intake volume as shown in FIG. 2, the second compressing compartment 32 has a reduced intake volume as shown in FIG. 3. In this state, when the rotational shaft 21 is rotated 180° more in a direction of arrow A, the intake volume of the second compressing compartment 32 is increased, whereas the intake volume of the first compressing compartment 31 is reduced. As such, since the intake volumes of the respective compressing compartments 31 and 32 operate in opposite fashions, if one of the compressing compartments 31 and 32 has an increased intake requirement for the gas due to an increased intake volume, the intake volume of the other compressing compartment is reduced, thereby providing a reduced intake requirement for the gas.

Meanwhile, a rapid increase in intake volume within the respective compressing compartments 31 and 32 is accompanied with a rapid increase in intake requirement for the gas through the first and second intake ports 61 and 62. However, since the size of the respective intake ports 61 and 62 is limited, an intake amount of the gas is insufficient, causing intake loss. In order to solve this problem, as shown in FIGS. 4 and 5, the present invention has a communication hole 71 formed adjacent to the intake ports 61 and 62 through the partition plate 35 such that the first and second compressing compartments 31 and 32 are communicated with each other via the communication hole 71.

As a result, when one of the compressing compartments is increased in intake volume and then has an increased intake requirement for the gas, the construction described above can allow the gas within the compressing compartment, which has a reduced intake requirement for the gas due to a reduced intake volume of the compressing compartment, to be supplied to the compressing compartment, which has a higher intake requirement (or intake volume) for the gas due to an increased intake volume of the compressing compartment through the communication hole 71, thereby preventing the intake loss. That is, even though the size of the intake ports 61 and 62 of the respective compressing compartments 31 and 32 is limited, the communication hole 71 allows the gas supplied through the intake ports 61 and 62 into the compressing compartments 31 and 32 to be shared by the compressing compartments 31 and 32 through the communication hole 71, so that, when the intake requirement for the gas is maximized in one of the compressing compartments 31 and 32, the gas can be sufficiently supplied into an associated compressing compartment 31 or 32, thereby preventing the intake loss.

For instance, in the case of a rapid increase in intake requirement for the gas due to an increase of the intake volume of the first compressing compartment 31, not only the gas supplied to the first compressing compartment 31 through the first intake port 61, but also some portion of the gas supplied to the second compressing compartment 32 through the second intake port 62 are supplied to the intake side of the first compressing compartment 31 through the communication hole 71, so that the intake loss can be prevented. On the contrary, when the second compressing compartment 32 has an increased intake volume, some portion of the gas supplied to the first compressing compartment 31 through the first intake port 61 is additionally supplied to the second compressing compartment 32 through the communication hole 71, so that the intake loss can be prevented.

In this case, in the present embodiment, the first and second compressing compartments 31 and 32 are, as shown in FIGS. 4 and 5, communicated with each other through the communication hole 71 formed adjacent to the first and second intake ports 61 and 62 through the partition plate 35 within the first and second compressing compartments 31 and 32. Meanwhile, as shown in FIG. 7, if a communication hole 72 is formed through an inner wall of the first and second compressing compartments 31 and 32 of the cylinder bodies 33 and 34 as well as the partition plate 35 to allow exits of the intake ports 61 and 62 to be communicated with each other, the same effect as that of the present embodiment can also be realized. However, in order to provide the construction shown in FIG. 7, the communication holes are drilled through not only the partition plate 35, but also the cylinder bodies 33 and 34, complicating the manufacturing process. Accordingly, it is desirable that the communication hole 71 is formed through the partition plate 35 such that the inner portions of the compressing compartments are directly communicated with each other via the partition plate 35, as shown in FIG. 4.

Moreover, as shown in FIG. 4, the communication hole 71 has a maximum width less than the thickness of the first and second ring pistons 42 and 52 in the radial direction. This is attributed to the fact that, if the width of the communication hole 71 is larger than the thickness of the ring pistons 42 and 52, compressing efficiency can be lowered because the compressed gas can flow from the respective compressing compartments 31 and 32 to the inner spaces of the respective ring pistons 42 and 52 through the communication hole 71, when the ring pistons 42 and 52 are located on the communication hole 71.

Moreover, the multi-cylinder rotary type compressor consistent with the invention has first and second cavities 73 and 74 recessed a predetermined depth on inner surfaces of the respective compressing compartments 31 and 32 in order to reduce the intake noise. The first and second cavities 73 and 74 are formed on the inner surfaces of the first and second shaft supporting members 36 and 37 at locations adjacent to the respective intake ports 61 and 62 while being opposite to the communication hole 71.

This construction can allow the first and second cavities 73 and 74 to act as a Helmholtz resonator upon generation of noise due to flow resistance of the intake gas at an initial stage of intake of the respective compressing compartments 31 and 32, thereby reducing intake noise of the gas. A typical Helmholtz resonator comprises a cavity with a small entrance, and reduces noise and vibration using a principle that, when an incidence wave within a specific frequency band comes into the cavity through the small entrance, a new reflection wave having a waveform opposite to that of the incidence wave is generated, and extinguishes the incidence wave as it comes out of the cavity.

In the present invention, the first and second cavities 73 and 74 act as the Helmholtz resonator described above. For example, when the second ring piston 52 passes the second cavity 74 as shown in FIG. 6, an entrance 74 a of the second cavity 74 is partially opened in a state of being screened by the second ring piston 52. At this time, the partially opened entrance 74 a of the second cavity 74 acts as the small entrance of the Helmholtz resonator, and an inner space 74 b of the second cavity 74 acts as the cavity of the Helmholtz resonator, so that the second cavity 74 can reduce the intake noise of the second compressing compartment 32 while acting as the Helmholtz resonator. The first cavity 73 also reduces the intake noise of the first compressing compartment 31 with the principle described above.

Under such a principle, it can be considered that, even though the first and second cavities 73 and 74 are not necessarily adjacent to the intake ports 61 and 62, respectively, these can act to reduce the noise generated from the compressing compartments 31 and 32. However, the noise related to intake of the gas in the rotary type compressor frequently occurs at the respective intake ports 61 and 62 having the maximum intake flow resistance. In particular, since the rotary type compressor of the invention has a large fluctuation in gas flow through the respective intake ports 61 and 62 at the moment that the compressor starts the intake operation, the intake noise is also increased at an initial time of the intake operation. Accordingly, in order to enhance the noise reduction effect of the intake gas, it is desirable that the first and second cavities 73 and 74 are located adjacent to the first and second intake ports 61 and 62, respectively, as illustrated in the present embodiments.

As apparent from the above description, in spite of the limited size of the intake ports, the multi-cylinder compressor of the present invention allows the gas, which is supplied to the respective compressing compartments through the respective intake ports, to be shared by the compressing compartments through the communication hole, so that, even when the intake requirement of any of the compressing compartments reaches the maximum point, the amount of the gas supplied to the associated compressing compartment is sufficiently secured, thereby preventing the intake loss.

Additionally, the gas supply into the compressing compartments can be smoothly performed, so that the intake noise caused by the intake flow resistance at the intake ports is minimized.

Furthermore, the first and second cavities are respectively provided on the inner surfaces of the compressing compartments so as to be adjacent to the intake ports, and act as a Helmholtz resonator, so that the intake noise can be further reduced.

Although exemplary embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 

1. A multi-cylinder rotary type compressor, comprising: first and second compressing compartments partitioned from each other; first and second intake ports communicated with the first and second compressing compartments, respectively; and a communication hole located adjacent to the first and second intake ports to communicate the first compressing compartment with the second compressing compartment.
 2. The compressor according to claim 1, further comprising: first and second cavities recessed a predetermined depth on an inner surface of the respective first and second compressing compartments so as to be adjacent to the communication hole.
 3. The compressor according to claim 2, wherein the first and second cavities are located opposite to the communication hole.
 4. The compressor according to claim 3, further comprising: first and second cylinder bodies constituting the first and second compressing compartments, respectively; first and second compressing devices disposed within the first and second compressing compartments, respectively; a rotational shaft penetrating through the first and second compressing compartments to drive the first and second compressing devices; a partition plate disposed between the first and second cylinder bodies; and first and second shaft supporting members provided opposite to the partition plate to close openings of the first and second compressing compartments, respectively, while supporting the rotational shaft.
 5. The compressor according to claim 4, wherein the communication hole is formed through the partition plate, and the first and second cavities are formed on inner surfaces of the first and second shaft supporting members, respectively, so as to be opposite to the communication hole.
 6. The compressor according to claim 5, wherein the first and second compressing devices comprise first and second eccentric portions provided to the rotational shaft within the first and second compressing compartments so as to be eccentric in opposite directions to the rotational shaft, respectively; first and second ring pistons coupled to outer surfaces of the first and second eccentric portions within the first and second compressing compartments, respectively; and first and second vanes to partition an inner space of the first and second compressing compartments while linearly traveling in a radial direction according to rotation of the ring pistons, respectively.
 7. The compressor according to claim 6, wherein the communication hole, and the first and second cavities have a maximum width less than a thickness of the ring pistons in the radial direction.
 8. The compressor according to claim 1, further comprising: first and second cylinder bodies to constitute the first and second cylindrical compressing compartments, respectively; first and second compressing devices installed within the first and second compressing compartments, respectively; and a rotational shaft installed to penetrate through the first and second compressing compartments in order to operate the first and second compressing devices; and a partition plate disposed between the first and second cylinder bodies, wherein the communication hole is formed through the partition plate so as to be adjacent to the intake ports.
 9. The compressor according to claim 8, wherein the first and second compressing devices comprise first and second eccentric portions provided to the rotational shaft within the first and second compressing compartments so as to be eccentric in opposite directions to the rotational shaft, respectively; first and second ring pistons coupled to outer surfaces of the first and second eccentric portions within the first and second compressing compartments, respectively; and first and second vanes to partition an inner space of the first and second compressing compartments while linearly traveling in a radial direction according to rotation of the ring pistons, respectively.
 10. The compressor according to claim 9, wherein the communication hole, and the first and second cavities have a maximum width less than a thickness of the ring pistons in the radial direction.
 11. A multi-cylinder rotary type compressor, comprising: first and second compressing compartments partitioned from each other; first and second compressing devices to perform compressing operation in a state of being eccentric in opposite directions within the first and second compressing compartments, respectively; first and second intake ports communicated with the first and second compressing compartments, respectively; and a communication hole located adjacent to the first and second intake ports to communicate the first compressing compartment with the second compressing compartment.
 12. The compressor according to claim 11, further comprising: a partition plate disposed between the first and second compressing compartments, wherein the communication hole is formed through the partition plate.
 13. The compressor according to claim 12, further comprising: first and second cavities recessed a predetermined depth on an inner surface of the respective first and second compressing compartments so as to be adjacent to the communication hole.
 14. The compressor according to claim 13, wherein the first and second cavities are located opposite to the communication hole. 